This application claims priority under 35 U.S.C. xc2xa7xc2xa7119 and/or 365 to 9903435-7 filed in Sweden on Sep. 21, 1999; the entire content of which is hereby incorporated by reference.
The present invention relates to portable communication apparatuses of the type having a main apparatus housing and a user interface comprising a keypad and a display.
Portable communication apparatuses of the kind described are of course commonplace. A well-known example is a cellular or mobile telephone, which operates for instance in a GSM system (Global System for Mobile communications in Europe) or D-AMPS (Digital Advanced Mobile Phone System, in the United States of America).
In addition to their basic role as a means for performing wireless communication of speech between human users, contemporary mobile telephones often provide a plurality of services other than just communication of speech. One very common service is the ability to send short text messages (for instance SMSxe2x80x94Short Messages Services in GSM), where a user of a telephone may generate a text message, containing a predetermined maximum number of alphanumeric characters, and then send it across the mobile telephone network to an intended receiver.
In a standard mobile telephone, the ordinary telephone keypad thereof will be used for entering the textstring (string of alphanumeric characters) to be incorporated in the message. Since an ordinary telephone keypad typically only contains keys for the digits 0 through 9, and a few other keys such as a * key and a # key, this limited set of different keys will have to represent a larger number of different alphanumeric characters, for instance the 25 different characters of the English alphabet.
In reality, each numeric key 0-9 must represent several different alphanumeric characters. For instance, the numeric key 2 may represent the alphanumeric characters A, B, C, as well as country-specific characters, such as xc3x81, xc3x81, AE, xc3xa1, xc3xa7, ┌, and also the digit 2. The user will choose between different characters by depressing the numeric key 2 for a different number of times in sequence.
The same approach is used for creating and editing entries in an electronic telephone book, which is normally included in the mobile telephone.
While many people use their mobile telephones mainly for speech calls, other user categories frequently use the above options for generating text messages and/or creating/editing entries in the electronic telephone book. In particular, people that have a mobile occupation or lifestyle are in many cases frequent users of such text-based services. Well-known examples of such people are young people (teenagers) and business people.
For frequent users of the text-based services of a mobile telephone, the ordinary telephone keypad is a far from perfect tool for inputting text into the mobile telephone. Having to press different keys repeatedly for different number of times is tedious, time-consuming and inefficient. Therefore, there is a pronounced need for an improved way of inputting text into a mobile telephone.
Moreover, the standard display of a mobile telephone normally has a restricted size and is therefore only capable of presenting a limited number of different characters at the same time.
A previously known solution to the problem of providing an improved user interface is a device, which is a combination between a mobile telephone and a portable computer. Such a device (often referred to as a personal digital assistantxe2x80x94PDA) is disclosed in EP-A-0 776 140 and comprises two separate user interfaces and an outer housing, which can be unfolded. When the outer housing is closed, the device has the appearance and size of an ordinary mobile telephone, wherein a first user interface is available, which substantially corresponds to an ordinary telephone user interface (i.e. a display and a numeric telephone keypad). When, on the other hand, the outer housing is unfolded, a second user interface is exposed, which offers a larger display and an alphanumeric keyboard. The alphanumeric keyboard and the large display of the second user interface may be used for inputting alphanumeric messages (textstrings), for instance for generating an SMS message or for manipulating an entry in an electronic telephone book. The large display of the second user interface may also be used in a graphic mode for displaying images etc.
While the device of EP-A-0 776 140 offers several useful features, it has a few distinct drawbacks for certain types of users. Firstly, the device is considerably more advanced than an ordinary mobile telephone. Consequently, the price thereof as well as the necessary knowledge level of the user is considerably higher than for an ordinary mobile telephone. Furthermore, the overall apparatus size, weight and power consumption are larger than for an ordinary mobile telephone.
Therefore, for users that either do not have enough money to buy an advanced PDA device known from EP-A-0 776 140, or simply do not find the various advanced features thereof to be of any particular usefulness from their personal point of view, the device of EP-A-0 776 140 does not represent an optimal solution to the problem of facilitating the input of text to a mobile telephone.
In view of the above, it is an object of the present invention to provide an accessory device, which will make it easier for a user of a mobile telephone to input text into the telephone, without having to rely solely on the ordinary numeric telephone keypad thereof.
Another object of the present invention is to provide a portable communication apparatus, which is more flexible than the prior art devices. More specifically, the portable communication apparatus shall appear in a compact size, having a low weight and a low power consumption, in situations where the user is only interested in normal telephony services (communication of speech). On the other hand, in situations where more advanced features than normal speech communication are required (such as text processing or presentation of graphic information), the portable communication apparatus shall provide a user interface, which in better for these services.
The above objects have been achieved by a portable communication apparatus, which has a main apparatus housing, a first user interface with a first keypad and a first display, and a second user interface with a second keypad and a second display, where the second keypad and the second display are detachably connectable to the main apparatus housing of the portable communication apparatus.
The objects are also achieved by the provision of an accessory device for a portable radio telephone of the above type, where the accessory device has a device housing comprising first and second housing portions, a second keypad is provided in the first housing portion, a second display is provided in the second housing portion, engagement means are provided for physically and operatively connecting the accessory device to the radio telephone, and controller means are adapted to receive keystrokes entered by the user on the second keypad and are also adapted to present the entered keystrokes on the second display.
Other objects, features and advantages of the present invention will appear from the following detailed disclosure of a preferred embodiment, from the drawings as well as from the attached subclaims.